I do have some size 30 Levis 521's and they fit me fine (from what I understand Levi's are vanity sized by 1?) Either way they stretched out to a 33+" waist after like 4 months of wear and its getting hard to keep them up even with a belt. :P I guess my point is that I would rather get them a half an inch small in the waist and let them stretch out a little bit rather than get half an inch too big and have them way to big in a couple months or do you think this is flawed?
Edit: This is definitely turning into a hard decision. I'll probably just go to Barneys and hopefully be able to try some on to compare.
This is probably your best bet. My advice is: try on a few pairs. If the waist needs to stretch out a little bit, that's fine. Waistbands are extremely rugged and take stretching well. I will say, though, having an exposed fly caused by too much stretching just looks sloppy IMO. Not a good look on anybody. If you can't get them to fit how you want in the legs without sizing down so much that you can't button them up, you're probably better off looking for a slimmer cut.
However, if you find a pair that limits your range of motion because of tightness in the thighs, crotch, and seat: do not expect them to stretch. Put them back on the rack and get a size larger. Otherwise you tempt fate in the form of a massive blowout.

Sizing down is not "bullshit". It doesn't work on all body types, especially with a cut as odd as the WG, but it works on a lot of people. The reason it doesn't work on you is because of your large thighs, but for anyone who doesn't have large thighs, it works.
It is a fact that WGs have a larger-than-tagged waist measurement, by about 2-3". Therefore, if you don't size down from your actual waist measurement, they will be 2-3" loose in the waist. For some people such as yourself, the thighs will prevent you from sizing down, and there is nothing wrong with that. But if you want the waist to fit, then you need to size down.
Here's a little misconception that I see a lot: Your "True waist" or "Actual waist" is *not* measured on your jeans. It is measured on YOU. The traditional way to do this is to measure at the belly button using one of these:
As I said earlier, tagged sizes run smaller because if your jeans measured exactly the same size as you, they would be skin tight. Literally. Add to the equation that a person's hips tend to have a larger circumference than their waist, and it's easy to see where that extra 2" goes. Note that last sentence doesn't necessarily apply to *all* body types.
For instance: my true waist is dead-on at 33.5". Where I wear my jeans, though, is actually closer to 35-36". Thus, I buy weird guys in a 33, and they fit perfectly. A person with smaller thighs than me could size down one more if they wanted a slimmer fit, but my argument is that this suggestion should not be "The Rule". Instead, it should just be "an option".
I can see where you're coming from though, but I think you misunderstood what I mean by "Sizing down". If you mean "size down from the measurement on your jeans", then I wholeheartedly agree. That is a good piece of advice...as if I was to buy a pair of 36's they'd hang down past my knees. It's when a person can't button up their jeans and the community pops in telling them to "stick with it because they'll be perfect" that I start to raise an eyebrow.
Now, I see the idea that "a person has to size down so much that it's difficult to button up their jeans or else they'll look awful later on down the road" pops up every now and then. I say *that* is bullshit. I went through that...I've gotten into my fair share of skin-tight jeans, expecting them to stretch out but experiencing nothing but a lot of discomfort and an eventual loss of money when I was forced to re-sell them.
To come around full circle here: my point is "it's all about the fit you want". If you want a slimmer fit, and have the wiggle room, go ahead and size down a little. However, you may want to consider looking for a slimmer cut. There's no sense in putting on a pair of weird guys and expecting them to be skinny. It's like expecting a pair of Levis 501's to have a modern fit. Or expecting a turtle to fly.
Sure, you can size the 501 down until it's a little more like a slim-taper, but it'll still have that anti-fit in the seat. Sure, you can throw a turtle, but it's just going to come crashing back to the earth, extremely annoyed. I should probably stop right here before this metaphor falls apart any more though.












